A229530 Number of defective 3-colorings of an n X 4 0..2 array connected horizontally, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.

6, 36, 361, 3064, 24344, 185808, 1379512, 10036352, 71892488, 508702512, 3563926872, 24764330720, 170893859240, 1172387842960, 8002259515128, 54379352988992, 368101566941512, 2483167144168432, 16699758317833368

Offset: 1

Author

R. H. Hardin, Sep 25 2013

Keywords

• nonn

Examples

			Some solutions for n=4:
..0..1..0..2....0..1..0..2....0..1..2..1....0..1..0..1....0..1..0..2
..0..1..0..1....0..2..0..1....2..1..0..1....0..2..0..2....0..2..0..1
..0..2..0..1....0..1..0..2....2..1..0..2....1..2..1..0....0..1..2..1
..1..1..0..2....0..1..2..1....0..1..2..1....1..2..1..0....2..1..0..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Column 4 of A229534.

Formula

Empirical: a(n) = 14*a(n-1) - 57*a(n-2) + 56*a(n-3) - 16*a(n-4) for n>5.

Empirical g.f.: x*(6 - 48*x + 199*x^2 - 274*x^3 + 105*x^4) / (1 - 7*x + 4*x^2)^2. - Colin Barker, Sep 18 2018